1. Field of Invention
The present invention relates to a power monitoring circuit. More particularly, the present invention relates to a power monitoring circuit having an automatic feedback and overload protection function.
2. Description of Related Art
With the development of electronic technology, the volume of electronic systems is getting smaller, but the amount of information to be processed is becoming larger day by day. A great amount of calculation results in overly large power consumption. Thus, heat generated by an electronic system becomes a serious problem. The life span of the electronic system may be reduced if it works at an overly high temperature. The heat may even damage the electronic system.
Therefore, an electronic system needs a power management device for effective power management. Conventionally, a laptop computer only measures the current and the voltage value of its power source and monitors the power source according to a safe range of the current value.
However, a laptop computer usually has two power supply systems: a battery and an AC power source. When the same power is consumed by the laptop computer, currents provided by the battery and the AC power source are different. Traditionally, monitoring the current value from the power source cannot satisfy both power supply systems. The conventional evaluation of power consumption calculated by the current value is overly high or overly low. In addition, conventional power systems cannot provide real time feedback. Some systems rely only on fuses to protect them from overload.